This invention relates generally to blood pressure measuring apparatus, and has particular reference to a novel electronic device that is capable of consistently measuring systolic and diastolic blood pressures with great accuracy.
Through the years, blood pressure has usually been measured by means of a standard pressure cuff and a stethoscope and the degree of accuracy of the measurement has depended to a great extent on the skill of the user of this equipment. More recently, a number of electronic blood pressure devices have been developed with the objective of producing accurate results even though operated by unskilled personnel. The sophisticated electronic devices are complex and relatively expensive and, unfortunately, quite frequently give erroneous readings caused by noise resulting from muscular movement or other spurious signals.
Electronic blood pressure devices are disclosed in U.S. Pat. Nos. 3,978,848 and 4,026,277 which represent the closest prior art known to the applicants. Neither of the devices disclosed by these patents utilizes a transducer that produces a waveform wherein the relationship of the amplitudes of the positive and negative pulses indicate the systolic and diastolic pressures. In addition to the foregoing, the following U.S. patents are considered by the applicants as being pertinent to the present invention: U.S. Pat. Nos. 3,930,494; 4,009,709; 4,011,860; 4,058,117; 4,074,711 and 4,078,551.